1. Field of the Invention
The present invention relates to a high frequency connector, and more particularly but not solely to a high frequency connector that is mounted on a circuit board of an electronic device, used as an access point for the communication between alien test equipment and the electronic device to inspect the inner circuit board via a mating connector.
2. Description of Related Art
High frequency connectors are typically mounting on PCBs, e.g. PCBs for mobile phones, where high frequency signals are passing through. In normal working state of the PCB, the connector is arranged to transmit signals, whereas in testing state of the PCB, the high frequency connectors are arranged as an access point to couple to a external test signal generator or other signal measurement equipment for testing the circuit section between two high frequency connectors and thus determine whether the circuit section is functioning properly. Therefore, the transmitting properties of the connector are crucial since the main task of the connector in the normal working state of the PCBs is transmitting signal, and thus it is desirable that loss of signal LOS can be minimized when high frequency signals pass through the connector.
A high frequency connector is disclosed by the applicant in its Chinese patent application No. CN 201038473 published on 19 Mar. 2008, the entire document incorporated herein by reference. Referring to FIG. 1 and FIG. 2, the connector disclosed comprising a shield 81, a first terminal 83, a second terminal 84 and an insulative housing 82 constructed by an insulating guide 821 and an insulating base 822; said shield 81 comprising a cylindrical connecting portion 811 and a shield base 812 formed under the cylindrical connecting portion 811. The shield 81 can be made of any conductive metal sheet and is functioned as a shield of electromagnetic radiation. The cylindrical connecting portion 811 is attached and electrically connected to the central conductor of a cable of a external testing equipment, and the shield 81 is electrically connected with its bottom to a earth welding on a PCB preferably by means of soldering such that a substantially closed shielding and earthing loop is formed and noise originated by electromagnetic radiation is greatly reduced. The insulating guide 821 is contained in the cylindrical connecting portion 811, where the insulating base 822 is fixedly attached in the shield base 812, and a base plate 823 can be attached to the bottom side of the insulating base 822.
The profile of the first terminal 83 and the second terminal 84 is shown in FIG. 2, wherein, the first terminal 83 and the second terminal 84 is extending across the opposite walls of the insulating base 822 respectively and into the insulating base 822 by insert-molding. The first terminal 83 comprising a first fixing section 831, a first contacting section 832 positioned on one side of the first fixing section 831 and bending downward to attach to one point the PCB, and a first spring section 832 positioned on the other side of the first fixing section 831 and is separated from the first fixing section 831 by a neck 834. The connection between the neck 834 and the first spring section 832 is thicker when compared with the neck 834 and the first fixing section 831 respectively. Preferably, the first spring section 832 is disposed at its distal end three contacting fingers 835. The second terminal 84 comprising a second fixing section 841, a second spring section 842 in “V” shape, and a second contacting section 843 bending downward to attach to another point on the PCB. The second fixing section 841 is separated from the second spring section 842 by a neck 844. And the second spring section 842 is thinner when compared with the first spring section 832.
When the connector as described is mounted onto the PCB both the first and the second terminal are soldered on the PCB, during the soldering process, however, respective slit may emerge between the terminals 83, 84 and the insulative housing 82 due to thermal expansion and contraction, through which the melting solder and flux may be drawn into the insulative housing 82 along the respective terminals. As a result, the mutually contact region on the respective terminals 83, 84, especially the first terminal 83 may be contaminated which in turn will increase the impedance in the region of the terminals. Either the increased impedance or vary of impedance along the terminals will degrade the quality of the high frequency signal passing there through.
Furthermore, it is to be noted in the above configuration that a neck of reduced dimension is provided between the second spring section 842 and the second fixing section 841, which may result in high impedance at this position due to the sharp cut-off and will thus degrade transmitting properties of the connector.
In addition, transitions are absent from the positions where the baseplate 823 and the guiding 821 is respectively attached to the insulating base 822 so that in case of loose fitting or deformation after long term use, dust may be absorbed into the insulative housing 822 and attached onto the terminals 83, 84. Attached dust particles may increase the impedance of the mutually contact regions of the terminals and will in turn degrade the transmitting properties of the conductor.